Go directly to the Pride and check in your luggage. They take the luggage in the multi-level parking garage. When you've gotten rid of the heavy stuff, take your carry-ons and walk toward the Pride. Keep looking for signs pointing to early check in at Queen Mary and follow them. When we were there, they weren't real obvious. You'll walk in through the dock level entrance at the back of QM. Carnival staff will be standing around, just keep walking straight in until you see the counter area for Carnival and walk up to one of the windows (or the line, if there is one). There will be a few staff members standing outside the room selling tickets to tour QM, if you so desire. They will even watch your carry on luggage while you're touring.